I have an idea. What if a SuperGroup could create Power Pools of these?
I guess they'd cost obscene amounts of Prestige to create and maintain (Power Pool upkeep?).
And when you use a power from your SG's pool, your SG gains some Prestige.
In-world explanation: "Hey, he's using the special jump-kick-aura-regen technique that only VillainGroup X uses!"
...Now I'm afraid that the Devs will turn the whole idea of signature powers into an SG thing. Don't do it, Devs! Not again!
Also, the OP mentioned putting a cap on the amount of "points" you could spend on a certain effect of the power. I beleive that a system similar to ED should be implemented: You can put any number of points into one area, but after 10 or so, they count for less.
........../signed.